Piston.



@LEVER E. BARTHEL. DETRUIT, MICHIGAN.

rrsroit.

Specicationof Letters Patent. y

Patente-dignity e, reir.

Application led August 31, 1914. Serial No. 859,273.

To all whom t may concern.'

Be it known that L OLIVER E. BARTHEL, a citizen of the United, States of America, residing at Detroit, in the county of Wayne and State of Michigan, have invented certain new and useful lmprovements in Pis- "tons, of which 4the following is a specification, reference being had therein to the vaccompanying drawings. p

My invention aims to provide a novel piston that can be advantageously used in connection with air pumps, compressors and the ,cylinders of various structures, without using packing rings and similar devices to insure .a non-leakable connection between the wall of a cylinder and the periphery of a piston. A

With this end in view, my invention further aims to provide a piston with expansible ends adapted to snugly engage the walls of a cylinder and prevent the passage of air, lubricant or other fluid between the cylinder walls and the piston. lt is in this connection7 that my invention has been primarily designed for an air pump utilized for supplying air to pneumatic tires. llt is essential in connection with this 'type of pump to exclude lubricant or other fluids from the air line, and l have found by` actual practice that an expansible feather edge in connection with a piston insures a more vpositive joint than packing and eliminates difficulties incident to the use of the same. l have also found that an annular feather edge at one end of a piston will provide an air tight connection with the cylinder wall and another annular feather edge at the opposite end of the piston a lubricantseal that prevents thepassa'ge of lubricants from one end of the piston to the other. llt is also possible to locate the air excluding structures at various points throughout the periphery of the piston and when so disposed tends to dissipate the heat of the .piston and preclude any excessive expansion or distortion.,

With these and'other results in view, ref- .erence will now be hadto the drawings,

whereinl one form of piston, and

Fi a similar view ofanotlierform numeral 1 denotes a cylindrical piston body;

" reciprocable in a cylinder 2 having air inlet Figure 1 is a vvertical. sectional view of' yton body.

4are form ports 3 and air exhaust ports 4. rlhe air exhaust ports 4 are preferably in a hollow plug or cap closing the end of the cylinder 2 and check valves of the conventional form are utilized for normally closing said ports. The piston body v1 has the outer end thereof provided with `an annular 'groove or recess 5 in proximity to the periphery of the piston body, whereby the outer wall 6 of the groove or recess will present a feather edge against the wall of the cylinder. The groove 5 is substantially V-shape in cross section whereby the inner side of the wall 6 of said groove will be disposed at an acute angle relative to the wall of the cylinder, thus permitting of the groove or recess being in such proximity to the periphery of the piston body as toform an expansible feather edge normally retained in snug engagement `with thewall of the cylinder by the partial compression of air therein.

. The inner end of the piston body 1 is counterbored to accommodate the end of a connecting rod 7 which is operatably connected to said piston body 'to reciprocate the` body snugly engages the walls of the cylinder 2 and besides maintaining a non-leakable or positive seal between the periphery of the body and the cylinder 2, said feather edge serves functionally as a scraper and prevents excessive accumulation of lubricant upon the walls of possibilityof lubricantnding its way to the outer end of the cylinderand entering an air line.

In Fig. 2 of the I,drawing there is illustrated a piston body 9 towhich is operatably connected a rod 10 for reciprocating the piston body within a cylinder 11. rll`he inner end of 'the piston body 9 has an annular feather edge or expansible wall 12 similar to the piston body 1 and coperatin wlth this expansible wall are annular. 'eather edges 13 adjacent the outer end of the pls- The annular feather edges 13 l d by providing the pistonv body with annular grooves 14 disposed a't an y .angle to the periphery of the. piston body,

. said grooves converging viding an annular wall 15 within the periphery of the piston body which forms a side of each of the grooves 14, one side of the Wall being of a greater depth than the other. The outer edge of the wal115 is flush with the periphery of the piston body and the' feather edges 13 formed by grooving the piston body have the same packing proclivities as the feather edges of the piston body 1. The groosves 14: form annular with the skirt or apron in forming a positive seal between the piston body and the cylinder.

While in the drawing there is illustrated 'the preferred embodiments of my invention, it is to be understood that the same are susceptible to such changes as are permissible by the appended claim..

What I claim is rlhe combination with acylinder and a connecting rod extending therein, of a one piece piston body having a flat outer closed end devoid of connections and protuberances and provided with an annular groove coperating with the periphery of the piston in forming an expansible air excluding Wall having afeather edge in engagement with the Wall of said cylinder, said wall having the feather edge thereof in a plane with the end of the piston body, and abored and interiorly stepped inner end having the inner 'bored portion thereof connected to said connecting rod and the extreme outer bored portion providing an eXpansible lubricant excluding skirt terminating in a feather edge in engagement with the Wall of the cylinder and coperating with the featherl edge at the outer end of said piston body in providing a positive seal between said piston body and said. cylinder.

lin testimony whereof ll affix my signature in presence of two witnesses.

t @LIVER E. BARTHEL. Witnesses:

ANNA M. Donn,

KARL H. BUTLER. 

